The Viruses and Cells Gordon Research Conference (GRC) is the premier meeting in the field of virology. The conference is small in size (<200 participants), but the presentations cover a wide range of viruses and address a breadth of topics in virology. These topics include virus entry, replication, assembly and egress; the manipulation and exploitation of the intracellular machinery; the stimulation and evasion of the host's intrinsic, innate and adaptive immune systems; mechanisms of pathogenesis; viral evolution and emergence; and the development and deployment of therapeutics and vaccines. The 2013 meeting will held at Il Ciocco, the GRC conference site in Barga, Italy from May 5 to 10. Invited speakers will present cutting-edge findings about the dynamic interactions of viruses with the cells and organisms they infect, as well as the host's arsenal of antiviral responses. Discussion leaders, chosen for their expertise in the topics covered in each session, will lead lively and open discussions following each presentation, which is a central and vital theme of the GRCs. In addition to the invited speakers, shorter talks will be chosen from the abstracts submitted for the poster sessions. Selections will be made to highlight exciting new developments in virus research, with an emphasis on showcasing younger scientists, including new investigators, postdoctoral fellows, and graduate students. The short talks will also be followed by active discussions led by the discussion leaders. The evening poster sessions, too, are an important and prominent aspect of the Viruses and Cells GRC. These sessions provide a relaxed and open environment in which participants can present and discuss their research. Meeting participants will include established and highly regarded investigators who have made seminal contributions to the field, young investigators launching independent research careers, postdoctoral fellows and graduate students, and investigators from industry. Funding is requested to provide partial support for conference fees and travel costs for participants, in particular for young investigators who have been invited as speakers or discussion leaders, as well as for promising new investigators, postdoctoral fellows, graduate students, and investigators from developing nations who will present short talks. The success and lasting impact of this meeting stems from its promotion of the free exchange of new ideas and discoveries in virology and the fostering of new and fruitful scientific collaborations.